ICSE Class 10 Answered
The sequence of events by which a cell duplicates its genome and synthesises all other cell contents and eventually divides into two daughter cells is called the cell cycle.
A typical eukaryotic somatic cell has two main stages—a long undividing state called the interphase also known as the intermitosis or I phase and a shorter phase of nuclear division called the mitotic or M phase.
Various phases of the cell cycle are regulated by proteins, cyclins and cyclin-dependent protein kinases (CDKs). · The CDKs phosphorylate proteins using ATP resulting in the breakdown of nuclear membrane. · Two regulatory mechanisms called check points are carried out by these CDKs. The first check point lies between the G1 and S phases and the second check point lies between the G2 and M phases. · The check points take decisions about the progress of cell division.